Dosage forms of bisphosphonates

ABSTRACT

Provided is an oral dosage form comprising a bisphosphonate selected from the group consisting of a risedronate and salts thereof; an ethylenediaminetetraacetic acid (EDTA) or a pharmaceutically acceptable salt thereof; and a delayed release mechanism to deliver the risedronate and the EDTA in the lower gastrointestinal tract, wherein the oral dosage form is administered according to a scheduled dosing interval. The present invention substantially alleviates the interaction between bisphosphonates and food or beverages, which interaction results in the bisphosphonate active ingredient not being available for absorption. The resulting oral dosage form may thus be taken with or without food. Further, the present invention effects delivery of the bisphosphonate and the chelating agent to the lower GI tract, substantially alleviating the upper GI irritation associated with bisphosphonate therapies. These benefits simplify previously complex treatment regimens and can lead to increased patient compliance with bisphosphonate therapies.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/637,100,filed Dec. 14, 2009, which is a continuation of application Ser. No.11/106,816, filed Apr. 15, 2005, now U.S. Pat. No. 7,645,459, whichclaims priority under Title 35, United States Code 119(e) fromProvisional Application Ser. No. 60/573,881, May 24, 2004 andincorporates by reference the entire disclosure of each of the mentionedprior applications.

FIELD OF THE INVENTION

The present invention relates to oral dosage forms of a bisphosphonatecomprised of a safe and effective amount of a pharmaceutical compositioncomprising a bisphosphonate, a chelating agent for enablingadministration of the bisphosphonate active ingredient with food orbeverages, means for effecting delayed release of the bisphosphonate andthe chelating agent in the lower gastrointestinal tract, and one or morepharmaceutically-acceptable excipients. The oral dosage forms of theinvention provide delivery of the pharmaceutical composition to thelower gastrointestinal tract of the mammal subject and providepharmaceutically effective absorption of the bisphosphonate whenadministered with or without food or beverages. The present inventionfurther relates to a method of treating or preventing diseasescharacterized by abnormal calcium and phosphate metabolism comprisingadministering to a human or other mammal in need thereof the oral dosageform described herein.

BACKGROUND OF THE INVENTION

Bisphosphonates were first developed to complex calcium in hard water toimprove detergent performance. Bisphosphonates have since been found tobe useful in the treatment and prevention of diseases or conditionscharacterized by abnormal calcium and phosphate metabolism. Suchconditions may be divided into two broad categories:

1. Conditions which are characterized by anomalous mobilization ofcalcium and phosphate leading to general or specific bone loss orexcessively high calcium and phosphate levels in the fluids of the body.Such conditions are sometimes referred to herein as pathological hardtissue demineralization.

2. Conditions which cause or result from deposition of calcium andphosphate anomalously in the body. These conditions are sometimesreferred to herein as pathological calcifications.

The first category includes osteoporosis, a condition in which bone hardtissue is lost disproportionately to the development of new hard tissue.Essential quantities of cancellous bone are lost, and marrow and bonespaces become larger, resulting in reduced cancellous bone strength.Bone also becomes less dense and fragile. Osteoporosis can besub-classified as senile, drug induced (e.g., adrenocorticoid, as canoccur in steroid therapy), disease induced (e.g., arthritic and tumor),etc., however the manifestations are similar. Another condition in thefirst category is Paget's disease (osteitis deformans). In this disease,dissolution of normal bone occurs, which is then haphazardly replaced bysoft, poorly mineralized tissue such that the bone becomes deformed frompressures of weight bearing, particularly in the tibia and femur.Hyperparathyroidism, hypercalcemia of malignancy, and osteolytic bonemetastasis are conditions also included in the first category.

The second category, involving conditions manifested by anomalouscalcium and phosphate deposition, includes myositis ossificansprogressiva, calcinosis universalis, and such afflictions as arthritis,neuritis, bursitis, tendonitis, and other inflammatory conditions whichpredispose involved tissue to deposition of calcium phosphates.

Bisphosphonates tend to inhibit the resorption of bone tissue, which isbeneficial to patients suffering from excessive bone loss. However, manyof the early bisphosphonates, such as ethane-1,1-diphosphonic acid(EHDP), propane-3-amino-1-hydroxy-1,1-diphosphonic acid (APD), anddichloromethane diphosphonic acid (Cl₂MDP), have the propensity ofinhibiting bone mineralization when administered at high dosage levels.Although more biologically potent bisphosphonates exist, which can beadministered at lower dosage levels (such as1-hydroxy-2-(3-pyridinyl)-ethylidene-1,1-bisphosphonic acid(risedronate), alendronate, ibandronate, and zoledronate), oraladministration of bisphosphonates sometimes results in patientcomplaints shortly after dosing. These complaints are usuallycharacterized by the patients as heartburn, esophageal burning, painand/or difficulty upon swallowing, and/or pain existing behind and/ormid-sternum. It is hypothesized that this irritation results from thebisphosphonate tablet adhering to epithelial and mucosal tissues,resulting in the topical irritation thereof. In order to avoid potentialupper gastrointestinal irritation, patients taking bisphosphonates areinstructed to take their medication with a full glass of water, and toremain upright for at least thirty minutes after taking an oral dose ofa bisphosphonate.

It is known that oral doses of bisphosphonates are poorly absorbed (lessthan 1% of the oral dose) in the gastrointestinal (GI) tract. See Ezraet al., Adv. Drug Del. Rev. 42: 175-95 (2000). Several approaches havebeen suggested for increasing absorption of oral bisphosphonatesthroughout the GI tract. These approaches include modifying thepermeability properties of the intestinal mucosa (e.g., through the useof absorption enhancers), or altering the physical or chemicalproperties of the bisphosphonate compounds themselves (e.g., throughprodrugs).

While the use of absorption enhancers, such asethylenediaminetetraacetic acid (EDTA), that increase intestinalpermeability at high doses, has been proposed as a means of increasingabsorption of oral bisphosphonates, the applicability of EDTA as anagent in human pharmacotherapy has been thought to be “impossible” inlight of the effects of EDTA on mucosal integrity. Ezra et al., Adv.Drug Del. Rev. 42: 185 (2000). Still others have concluded that the highamount of EDTA required to effect an increase in GI absorption wouldexclude the agent as a candidate for use in oral bisphosphonatetherapies. See Janner et al., Calcif. Tissue Int. 49: 280-83 (1991).

While the primary site of bisphosphonate absorption is the smallintestine, bisphosphonates such as risedronate have similar absorptionthroughout the small intestine independent of where it was delivered.See Mitchell et al., Pharm Res., Vol. 15, No. 2: 228-232 (1998). Thustargeted delivery of the bisphosphonate alone to the small intestinewould not increase absorption or efficacy of the bisphosphonate.However, others have attempted to increase the absorption ofbisphosphonates by increasing the permeability of the intestinal mucosathrough delivery of microparticles of chelating agents andbisphosphonate to the reported site of absorption (BR2001-006601).

Bisphosphonates such as risedronate and alendronate have been approvedby a number of regulatory agencies as being effective in the treatmentof various bone pathologies. However, interactions betweenbisphosphonates and foods and minerals (especially cations like calcium,magnesium, aluminum, and iron-containing foods or supplements) causeless of the bisphosphonate to be available for absorption. For example,in Mitchell et. al., Br. J. Clin. Pharmacol. 48: 536-542 (1999), it wasdemonstrated that administration of risedronate within 30 minutes of ameal reduced the amount absorbed by 50% compared to administration inthe fasting state. In order to reduce this food effect, the labeling oforal bisphosphonate products instruct patients to take their medicationat least thirty minutes or in the case of Ibandonate sixty minutes,before the first food of the day, and are instructed to take theircalcium supplements at another time of the day, or on a day when theyare not taking an oral dose of a bisphosphonate. These dosinginstructions can seem complex and inconvenient to the patient, which canlead to poor patient compliance.

There is an ongoing need to develop an oral dosage form of abisphosphonate which can be taken with or without food or beverages(i.e. has pharmaceutically effective absorption regardless of food orbeverage intake), at the preference of the patient, and which does notproduce upper gastrointestinal irritation.

It has been found that a pharmaceutical composition comprising abisphosphonate, a sufficient amount of chelating agent to bind the ionsand minerals in food, and a means for effecting delayed release of thebisphosphonate and the chelating agent in the lower gastrointestinaltract is useful in providing an oral dosage form which provides deliveryof the bisphosphonate to the lower gastrointestinal tract, as well aspharmaceutically effective absorption of the bisphosphonate whenadministered with or without food or beverages. The oral dosage forms ofthe present invention may be taken with or without food or beverages,thus simplifying the bisphosphonate treatment therapy and leading toincreased patient compliance and convenience. Further, the oral dosageforms of the invention provide for delayed release of the bisphosphonateand the chelating agent in the lower gastrointestinal tract, which mayalleviate the upper gastrointestinal irritation experienced with otheroral bisphosphonate dosage forms and the need to remain upright forthirty minutes post-dose administration.

SUMMARY OF THE INVENTION

The present invention relates to an oral dosage form of a bisphosphonateactive ingredient comprising a safe and effective amount of apharmaceutical composition comprising:

(a) a bisphosphonate;

(b) from about 10 mg to about 1000 mg of a chelating agent; and

(c) a delayed release mechanism to deliver the bisphosphonate and thechelating agent in the lower gastrointestinal tract.

The dosage forms of the present invention provide delivery of thebisphosphonate and the chelating agent to the lower gastrointestinaltract of the mammal subject and pharmaceutically effective absorption ofthe bisphosphonate active ingredient when administered with or withoutfood or beverages.

The present invention substantially alleviates the interaction betweenbisphosphonates and food, which interaction results in decreasedabsorption of the bisphosphonate active ingredient. The resulting noveloral dosage form may thus be taken with or without food or beverages,which simplifies previously complex treatment regimens and can lead toincreased patient compliance with bisphosphonate therapies and if thepatients are compliant their disease can be better treated. Theinvention further alleviates the potential for upper gastrointestinalirritation associated with immediate release oral dosage forms ofbisphosphonates, by delaying release of the bisphosphonate activeingredient until the bisphosphonate and the chelating agent reach thelower gastrointestinal tract.

The present invention further relates to a method of treating orpreventing diseases characterized by abnormal calcium and phosphatemetabolism comprising administering to a human or other mammal in needthereof the oral dosage form described herein.

The invention further relates to a kit comprising one or more oraldosage forms of the present invention and means for facilitatingcompliance with methods of this invention.

DETAILED DESCRIPTION OF THE INVENTION Definitions and Usage of Terms

The term “bolus” as used herein means that release of a significantamount of the bisphosphonates and/or chelating agent is achieved at thesite of initiation/release.

The terms “continuous” or “continuously,” as used herein, mean atregular specified intervals. For example, a continuous scheduleaccording to a dosing regimen of once weekly means that the active isgiven one time per week for an unspecified period of time or for as longas treatment is necessary.

The term “nutrient,” as used herein, means any nutritional or dietarysupplement including but not limited to vitamins, minerals, amino acids,herbs or other botanicals, or concentrates, metabolites, constituents,extracts, or combinations of the same.

The term “pharmaceutical composition,” as used herein, means an oraldosage form comprised of a safe and effective amount of a bisphosphonateactive ingredient and one or more pharmaceutically-acceptable excipientsincluding at least one chelating agent. The pharmaceutical compositionsdescribed herein are comprised of from 0.5% to 75%, preferably from 1%to 40% of a bisphosphonate active ingredient and from 25% to 99.5%,preferably from 60% to 99% of pharmaceutically-acceptable excipientsincluding at least one chelating agent.

The term “safe and effective amount,” as used herein, means an amount ofa compound or composition high enough to significantly positively modifythe symptoms and/or condition to be treated, but low enough to avoidserious side effects (at a reasonable risk/benefit ratio), within thescope of sound medical judgment. The safe and effective amount of activeingredient for use in the method of the invention herein will vary withthe particular condition being treated, the age and physical conditionof the patient to be treated, the severity of the condition, theduration of the treatment, the nature of concurrent therapy, theparticular active ingredient being employed, the particularpharmaceutically-acceptable excipients utilized, and like factors withinthe knowledge and expertise of the attending physician.

The term “sustained release” means that the bisphosphonate and/orchelating agent are not substantially released at the site of initiationbut continues to be released from the initiation site throughout theremainder of the GI tract.

The term “pharmaceutically effective absorption” as used herein means anamount of a chelating compound high enough to significantly bind themetal ions and minerals in food but low enough not to significantlyalter absorption of the bisphosphonate as compared to absorption in thefasted state. That is, absorption is similar with or without food. Giventhe high variability of bisphosphonate absorption, fed exposure withinabout 50% of fasting exposure is expected to be pharmaceuticallyeffective absorption.

The term “oral dosage form,” as used herein, means any pharmaceuticalcomposition intended to be administered to the lower gastrointestinaltract of a human or other mammal via the mouth of said human or othermammal. For the purposes of the present invention, the delivered formcan be in the form of a compressed tablet containing granules orparticles of a bisphosphonate and a chelating agent, a capsule (e.g.,soft gelatin or hard gelatin, consisting of starch, orhydroxypropylmethylcellulose) which contains beads, particles, orsuspensions of the bisphosphonate and the chelating agent, or a dry mixcontaining granules or particles of bisphosphonate and chelating agentfor making a reconstituted suspension in water (e.g., a sachet).

The term “unit dose” or “unit dosage” means a dosage form containing anamount of pharmaceutical active or nutrient suitable for administrationin one single dose, according to sound medical practice. The presentinvention is particularly useful for the administration of unit doses inthe form of tablets and capsules.

The term “gastrointestinal tract” or “GI tract,” as used herein, relatesto the alimentary canal, i.e., the musculo-membranous tube about thirtyfeet in length, extending from the mouth to the anus. The term “uppergastrointestinal tract,” as used herein, means the buccal cavity, thepharynx, the esophagus, and the stomach. The term “lowergastrointestinal tract,” as used herein, means the small intestine andthe large intestine.

The term “small intestine,” as used herein, means the part of the lowergastrointestinal tract consisting of the duodenum, the jejunum, and theileum, i.e., that portion of the intestinal tract just distal to theduodenal sphincter of the fundus of the stomach and proximal to thelarge intestine.

The term “large intestine,” as used herein, means the part of the lowergastrointestinal tract just distal to the small intestine, beginningwith the cecum, including the ascending colon, the transverse colon, thedescending colon, the sigmoid colon, and the rectum.

Bisphosphonate Active Ingredient

The terms “bisphosphonate” and “diphosphonate,” as used herein, includeacids, salts, esters, hydrates, polymorphs, hemihydrates, solvates, andderivatives thereof. The bisphosphonates of the present inventioninclude those preferred compounds containing a nitrogen atom.Non-limiting examples of bisphosphonates useful herein include thefollowing: 1-hydroxy-2-(3-pyridinyl)-ethylidene-1,1-bisphosphonic acid(risedronate) as described in U.S. Pat. No. 5,583,122, to Benedict etal., issued Dec. 10, 1996; U.S. Pat. No. 6,410,520 B2, to Cazer et al.,issued Jun. 25, 2002; 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid(alendronic acid or alendronate) as described in U.S. Pat. No.4,621,077, to Rosini et al., issued Nov. 4, 1986; U.S. Pat. No.6,281,381 B1, to Finkelstein et al., issued Aug. 28, 2001; U.S. Pat. No.6,008,207, to Brenner et al., issued Dec. 28, 1999; U.S. Pat. No.5,849,726, to Brenner et al., issued Dec. 15, 1998; U.S. Pat. Pub.2001/0021705 A1, by Brenner et al., published Sep. 13, 2001; U.S. Pat.No. 4,922,007, to Kieczykowski et al., issued May 1, 1990; U.S. Pat. No.5,019,651, to Kieczykowski, issued May 28, 1991;3-amino-1-hydroxypropylidene-1,1-bisphosphonic acid (pamidronate) asdescribed in U.S. Pat. No. 4,639,338, to Stahl et al., issued Jan. 27,1987; (4-chlorophenyl)thiomethane-1,1-diphosphonic acid (tiludronate) asdescribed in U.S. Pat. No. 4,876,248 to Breliere et al., issued Oct. 24,1989; 1,1-dichloromethylene-1,1-diphosphonic acid (clodronate) asdescribed in U.S. Pat. No. 3,422,021;cycloheptylaminomethylene-1,1-bisphosphonic acid (cimadronate), asdescribed in U.S. Pat. No. 4,970,335, to Isomura et al., issued Nov. 13,1990; 1-hydroxy-3-(N-methyl-N-pentylamino)propylidene-1,1-bisphosphonicacid (ibandronate), which is described in U.S. Pat. No. 4,927,814,issued May 22, 1990; 1-hydroxy-2-(imidazol-1-yl)ethane-1,1-bisphosphonicacid (zoledronate); and1-(N-phenylaminothiocarbonyl)methane-1,1-bisphosphonic acid.

In one embodiment of the invention, the bisphosphonate is selected fromthe group consisting of risedronate, alendronate, pamidronate,tiludronate, cimadronate, ibandronate, clodronate, zoledronate, andsalts, esters, hydrates, hemihydrates, polymorphs, and solvates thereof,and combinations thereof.

It should be noted that the terms “bisphosphonate” and“bisphosphonates,” as used herein in referring to the therapeutic agentsof the present invention are meant to also encompass diphosphonates,biphosphonic acids, and diphosphonic acids, as well as salts, esters,hydrates, polymorphs, hemihydrates, solvates, and derivatives of thesematerials.

Non-limiting examples of bisphosphonate salts useful herein includethose selected from the group consisting of alkali metal, alkalinemetal, ammonium, and mono-, di-, tri-, or tetra-C1-C₃₀-alkyl-substitutedammonium. Preferred salts are those selected from the group consistingof sodium, potassium, and ammonium salts.

The amount of bisphosphonate active ingredient contained in the oraldosage forms of the present invention will depend on the particularbisphosphonate selected and the continuous dosing schedule upon whichthe bisphosphonate is dosed to the patient. Continuous dosing schedulesof daily, weekly, twice monthly, three times per month, and once monthlyare non-limiting examples of dosing regimens suitable for use with theoral dosage forms of the present invention. The terms “three times permonth” or “thrice monthly” mean that an oral dosage form is administeredthrice, i.e., three times, during a monthly calendar period. In a thricemonthly schedule, the oral dosage forms may be administered on threeconsecutive days, or once about every nine to eleven days. The terms“twice per month” or “twice monthly” mean that an oral dosage form isadministered twice, i.e., two times, during a monthly calendar period.In a twice monthly regimen, the oral dosage forms may be administered onconsecutive days or once about every fourteen to sixteen days. The terms“monthly” or “once monthly” mean that an oral dosage form isadministered once, i.e., one time during a monthly calendar period, thatis, about every 28 to 31 days.

The use of a specific nomenclature in referring to the bisphosphonate orbisphosphonates is not meant to limit the scope of the presentinvention, unless specifically indicated. Mixed nomenclature iscurrently in use by those of ordinary skill in the art, for examplereference to a specific weight or percentage of a bisphosphonate activeingredient is on an anhydrous monosodium salt basis for risedronate andon an anhydrous free acid basis for Alendronate. For the presentinvention, the phrase “about 35 mg of a bone resorption inhibitingbisphosphonate selected from the group consisting of risedronate,pharmaceutically acceptable salts thereof, and mixtures thereof, on ananhydrous monosodium salt basis” means that the amount of thebisphosphonate compound selected is calculated based on about 35 mg ofanhydrous risedronate monosodium salt. The phrase “about 70 mg of a boneresorption inhibiting bisphosphonate selected from the group consistingof alendronate, pharmaceutically acceptable salts thereof, and mixturesthereof, on an anhydrous acid basis” means that the amount of thebisphosphonate compound selected is calculated based on about 70 mg ofanhydrous alendronic acid.

Generally, the oral dosage forms of the present invention will containfrom about 1 mg to about 500 mg of a bisphosphonate on an anhydrousweight basis. When the bisphosphonate is dosed on a daily basis, theoral dosage form contains from about 1 mg to about 100 mg bisphosphonateon an anhydrous weight basis. When the bisphosphonate is dosed on aweekly basis, the oral dosage form contains from about 10 mg to about200 mg bisphosphonate on an anhydrous weight basis. When thebisphosphonate is dosed on a twice monthly basis, the oral dosage formcontains from about 20 mg to about 300 mg bisphosphonate on an anhydrousweight basis. When the bisphosphonate is dosed three times per month,the oral dosage form contains from about 15 mg to about 250 mgbisphosphonate on an anhydrous weight basis. When the bisphosphonate isdosed on a monthly basis, the oral dosage form contains from about 50 mgto about 500 mg on an anhydrous weight basis.

When the bisphosphonate active ingredient is risedronate, a daily oraldosage form of the present invention contains from about 1 mg to about10 mg risedronate on a risedronate anhydrous monosodium salt basis. Aweekly oral dosage form contains from about 10 to about 50 mgrisedronate on a risedronate anhydrous monosodium salt basis. A twicemonthly oral dosage form contains from about 20 to about 100 mgrisedronate, preferably about 75 mg on a risedronate anhydrousmonosodium salt basis. An oral dosage form that is administered threetimes per month contains from about 15 to about 75 mg risedronate,preferably about 50 mg risedronate on a risedronate anhydrous monosodiumsalt basis. A monthly oral dosage form contains from about 50 to about200 mg risedronate, preferably from about 100 to about 175 mgrisedronate, and more preferably about 150 mg risedronate on arisedronate anhydrous monosodium salt basis.

Chelating Agent

The term “chelating agent,” as used herein, means a molecule containingtwo or more electron donor atoms that can form coordinate bonds to asingle metal ion. The term “chelating agent” is understood to includethe chelating agent as well as salts thereof. For example, the term“chelating agent” includes citric acid as well as its salt forms.

The most common and widely used chelating agents coordinate to metalatoms through oxygen or nitrogen donor atoms, or both. Other less commonchelating agents coordinate through sulfur in the form of —SH (thiol ormercapto) groups. After the first coordinate bond is formed, eachsuccessive donor atom that binds creates a ring containing the metalatom. A chelating agent may be bidentate, tridentate, tetradentate,etc., depending upon whether it contains two, three, four, or more donoratoms capable of binding to the metal atom. See Kirk-Othmer Encyclopediaof Chemical Technology (4th ed. 2001).

In homogeneous dilute solutions, the equilibrium constant for theformation of the complex from the solvated metal ion (e.g., calcium) andthe chelating agent in its fully dissociated form is called theformation or stability constant, K. The practical significance offormation constants is that a high log K value means a large ratio ofchelated to unchelated (or free) metal ion, when equivalent amounts ofmetal ion and chelating agent are present. Higher ratios (or differenceif K is expressed in log units) of the chelating agent and thebisphosphonate complexation constants are preferred in order to havenearly all of the metal ion complexed to the chelating agent instead ofthe bisphosphonate. For example, for equal molar amounts of bothbisphosphonate and the chelating agent, in order for the metal ions tobe 99% complexed to the chelating agent, the chelating agent must have alog K which is at least 4 units higher than the bisphosphonate-metal ioncomplex. The other technique which can be used to favor the chelatingagent-metal ion complex over that of the bisphosphonate-metal ioncomplex is to add a molar excess of the chelating agent which relies onthe law of mass action to favor formation of the chelating agent-metalion complex.

Although pH and solution concentration can affect the formationconstant, in general, the log K of the chelating agent is preferably atleast equal to that of the bisphosphonate. In other instances the log Kof the chelating agent is 2 to 5 units higher than that of thebisphosphonate. In other instances, the chelating agent is present at amolar excess to that of the bisphosphonate. The chelating agent in suchinstances is present in at least a 2:1 molar ratio of the chelatingagent to bisphosphonate.

The chelating agent may be soluble or insoluble in the gastrointestinaltract as long as it is readily available for complexation with metalions in the food. In one instance a chelating agent that is soluble inthe gastrointestinal tract is used because chelating agents that arepoorly soluble may be too slowly available to complex a significantportion of the calcium in the coadministered food. In other instancesthe chelating agent should have a solubility comparable to or greaterthan that of the bisphosphonate so that it can be present in itscomplexing form at concentrations at least equal to that of thebisphosphonate,

Various classes of chelating agents are suitable for use in the presentinvention. Non-limiting examples of these classes include polyphosphates(e.g., sodium tripolyphosphate, hexametaphosphoric acid, sodium acidpyrophosphate, sodium pyrophosphate, tetra sodium pyrophosphate, sodiumhexametaphosphate, sodium metaphosphate); aminocarboxylic acids (e.g.,ethylenediaminetetraacetic acid (EDTA),1,2-bis(2-amino-phenoxy)ethane-N,N,N′N′-tetraacetic acid (EGTA),ethylenebis(oxyethylenenitrilo)tetraacetic acid (BAPTA),N-(hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA),diethylenetriaminepentaacetic acid (DTPA), N-dihydroxyethylglycine(2-HxG), ethylenebis(hydroxyphenyl-glycine) (EHPG), glutamic acid,aspartic acid, glycine, lysine); 1,3-diketones (e.g., acetylacetone,trifluoroacetylacetone, thenoyltrifluoroacetone, ascorbic acid);hydroxycarboxylic acids (e.g., tartaric acid, citric acid, malic acid,gluconic acid, ferulic acid, lactic acid, glucuronic acid); polyamines(e.g., dietheylenetriamine, triethylenetriamine); aminoalcohols (e.g.,triethanolamine, N-hydroxyethylethylene-diamine, aminoethylethanolamine(AEEA); phenols (e.g., disulfopyrocatechol, chromotropic acid);aminophenols (e.g., oxinesulfonic acid); Schiff bases (e.g.,disalicylaldehyde 1,2-propylenediimine); tetrapyrroles (e.g.,tetraphenylporphin, phthalocyanine); silicates (aluminum calciumsilicate, calcium silicate, sodium aluminosilicate sodium calciumaluminosilicate (hydrates), tricalcium silicate); sulfur compounds(e.g., potassium ethyl xanate, sodium diethyldithiocarbamate, diethyldithiophosphoric acid, thiourea, magnesium sulfate); syntheticmacrocyclic compounds (e.g., hexamethyl-[14]-4,11-dieneN₄,2.2.2-cryptate); polymers (e.g., polyethyleneimines,polymethacryloylacetone, poly(p-vinylbenzyliminodiacetic acid)),phosphonic acids (e.g., nitrilotrimethylenephosphonic acid,ethylenediaminetetra-(methylenephosphonic acid),hydroxyethylidenediphosphonic acid).

In one embodiment, the chelating agent is selected from the groupconsisting of EDTA, citric acid, malic acid, tartaric acid, lactic acid,adipic acid, succinic acid, aspartic acid, glutamic acid, lysine, sodiumhexametaphosphate, and combinations thereof. In another embodiment, thechelating agent is EDTA, citric acid, or sodium hexametaphosphate.

In another embodiment of the invention, a monodentate chelating agentwhich often precipitate as metal ion complexes, may be used in place ofa polydentate chelating agent. Suitable monodentate complexing agentsinclude, but are not limited to, phosphates (e.g., sodium phosphate,sodium aluminum phosphate, sodium acid phosphate, dipotassium phosphate,disodium phosphate, monobasic) and carboxylic acids (e.g., acetic acid).

The amount of chelating agent present in the oral dosage form of thepresent invention will depend on the particular chelating agent oragents (i.e. mixtures of chelating agents) selected, the amount ofbisphosphonate active ingredient present in the oral dosage form, andthe specific portion of the lower GI tract where delivery of thechelating agent and/or bisphosphonate active ingredient is desired.After the ingestion of milk, it has been shown in the art that theconcentration of calcium decreases over the length of the lower GItract, beginning with the small intestine and proceeding through to theend of the large intestine. Mahe, J. et al., Gastroileal nitrogen andelectrolyte movements after bovine milk ingestion in humans, Am. J.Clin. Nutr. 56: 410-16 (1992). Thus, for example, a lower concentrationof a particular chelating agent may be required to effect delivery ofthe bisphosphonate to the transverse colon, as compared with theconcentration of that same chelating agent required to effect deliveryof the bisphosphonate to the terminal ileum, given the same dose ofbisphosphonate active ingredient.

Generally, the oral dosage forms of the present invention will contain asafe and effective amount of a chelating agent suitable for achievingthe desired chelating effect, that is, chelating the residual metal ionsthat are present in the gastrointestinal tract from food at the site ofdelivery without significantly affecting the absorption of thebisphosphonate had no food been present. In one embodiment, the oraldosage form contains from about 10 mg to about 1000 mg of a chelatingagent per unit dose. In another embodiment, the oral dosage formscontain from about 10 mg to about 500 mg of a chelating agent per unitdose. When the chelating agent is disodium EDTA, the preferred range isfrom about 55 mg to about 500 mg, preferably from about 75 mg to about250 mg per unit dose. When the chelating agent is citric acid, thepreferred range is from about 100 mg to about 1000 mg, preferably fromabout 250 mg to about 500 mg per unit dose.

Delayed Release in the Lower Gastrointestinal Tract

A human or other mammal suffering from diseases or disorders involvingcalcium and phosphate metabolism can be successfully treated by thedelivery of the bisphosphonate active ingredient to the lower GI tractof said human or other mammal. The novel dosage forms described hereineffect delivery to the lower GI tract, and prohibit the undesiredrelease of bisphosphonate in the mouth, pharynx, esophagus, and/orstomach, thereby prohibiting the erosion, ulceration, or other likeirritation of the epithelial or mucosal layers of these tissues. In someinstances, it may be desirable to effect delivery of the bisphosphonateand the chelating agent to the small intestine or a particular segmentof the small intestine, (e.g., the terminal ileum). In other cases, itmay be desirable to effect delivery of the bisphosphonate and thechelating agent to the entire lower GI tract or to a segment of the GItract, beginning with delivery to the small intestine and continuingwith delivery if needed to the large intestine. In yet other cases itmay be desirable to effect a bolus delivery of the bisphosphonate andchelating agent to the lower GI or to specific segments of the lower GItract. In one embodiment of the invention, delivery of the activebeginning in the small intestine and continuing through to the largeintestine may be accomplished through the use of sustained releaseformulations known to those skilled in the art. Such sustained releaseformulations are designed to slow the release of the bisphosphonate andthe chelating agent over a specified time period, as the oral dose formprogresses through the lower GI tract. In still other instances, it maybe desirable to achieve delivery of the bisphosphonate and the chelatingagent to the large intestine or a particular segment thereof (e.g., theascending colon). In still other instances, it may be desirable todeliver the chelating agent and the bisphosphonate in a bolus amount tothe large intestine. In still other instances, it may be desirable todeliver the chelating agent to one segment of the lower GI tract, and todeliver the bisphosphonate to a different segment of the lower GI tract.For example, it may be desirable to deliver the chelating agent to theterminal ileum and the bisphosphonate to the ascending colon.

The term “delayed release,” as used herein, refers to a delivery of abisphosphonate active ingredient and a chelating agent which is achievedby formulating the pharmaceutical composition comprising thebisphosphonate and the chelating agent so that their release will beaccomplished at some generally predictable location in the lower GItract more distal to that which would have been accomplished had therebeen no alteration in the delivery of the bisphosphonate and thechelating agent.

In another embodiment of the invention, the bisphosphonate and thechelating agent may be administered to a mammal subject by way of morethan one oral dosage form, each of which comprises a means fordelivering the contents of said oral dosage form to the lower GI tract.For example, a patient may take a unit dosage of a bisphosphonate,followed by a separate unit dose containing the chelating agent.

In yet another embodiment the chelant and bisphosphonate are releasedrapidly and as close to simultaneously as possible. This causes thelocal concentration of chelating agent to be higher in relationship tothe metal ions in the food. The higher local concentration of chelatingagent in the environment where the active is released may moreeffectively complex the metals in the food and facilitate absorption ofthe bisphosphonate. This can be conveniently achieved from a singletablet.

Various means for targeting release of the bisphosphonate and thechelating agent in the lower GI tract are suitable for use in thepresent invention. Non-limiting examples of means for delivery to thelower GI tract include pH triggered delivery systems, dose forms fromwhich the release of drug is triggered by the action of bacterialenzymes, and time dependent delivery systems.

In some cases it may be desirable to initiate release of thebisphosphonate and chelating agent primary in the duodenum and/or thejejunum. In other instances it is desirable to primarily initiaterelease of the bisphosphonate and chelating agent in the mid-jejunumand/or the terminal ileum. In yet other cases it may be desirable toprovide a sustained release of the bisphosphonate and the chelatingagent primarily in the jejunum throughout the terminal ileum. Forprimary colonic delivery it may be desirable to initiate release of thebisphosphonate and chelating agent in the ascending and/or transversecolon.

pH Triggered Delivery Systems

One embodiment of the present invention involves coating (or otherwiseencapsulating) the bisphosphonate and the chelating agent(s) with asubstance which is not broken down, by the gastrointestinal fluids torelease the bisphosphonate and the chelating agent until a specificdesired point in the intestinal tract is reached. In one embodiment,delayed release of the pharmaceutical composition is achieved by coatingthe tablet, capsule, or particles, granules, or beads of thebisphosphonate and the chelating agent with a substance which is pHdependent, i.e., broken down or dissolves at a pH which is generallypresent in the lower GI tract, but not present in the upper GI tract(i.e., the mouth, buccal cavity, pharynx, esophagus, or stomach).

In some cases, it may be desirable that the bisphosphonate and thechelating agent are released at a particular location in the small orlarge intestine. In other cases, it may be desirable to release thebisphosphonate and the chelating agent independently at differentlocations within the lower GI tract. For example, it may be desirable torelease the chelating agent in the ascending colon, and thebisphosphonate in the transverse colon. When targeted release of thebisphosphonate and the chelating agent together or separately inparticular locations within the lower GI tract is desired, the selectionof the coating material and/or the method of coating or otherwisecombining the bisphosphonate and the chelating agent with the selectedcoating material or other pharmaceutically-acceptable excipients may bevaried or altered as is described herein, or by any method known to oneskilled in the art.

The ultimate site of and/or the rate of delivery in the lower GI tractcan be satisfactorily controlled by one skilled in the art, bymanipulating any one or more of the following:

(a) the active ingredient proper;

(b) the type and level of disintegrant;

(c) the type of coating, the type and level of excipients added to thecoating and the concomitant desirable thickness and permeability(swelling properties) of the coating;

(d) the time dependent conditions of the coating itself and/or withinthe coated tablet, particle, bead, or granule;

(e) the particle size of the granulated active ingredient; and

(f) the pH dependent conditions of the coating itself and/or within thecoated tablet, particle, bead, or granule.

In particular, solubility, acidity, and susceptibility to hydrolysis ofthe different bisphosphonate active ingredients, such as acid additionsalts, salts formed with the phosphonic group (e.g., alkali metal salts,alkaline earth metal salts, etc.), and esters (e.g., alkyl, alkenyl,aryl, arylalkyl) may be used as guidelines for the proper choice. Inaddition, suitable pH conditions might be established within the coatedtablets, particles, granules, or beads by adding a suitable buffer tothe active ingredient in accordance with the desired release pattern.

Besides the above-mentioned variations in order to obtain the desiredrelease pattern, the excipients may also be varied, as long as they donot affect the activity of the particular bisphosphonate selected.

One embodiment of the present invention is delivered to the lower GItract utilizing a pH dependent enteric coating material made from apartly methyl esterified methacrylic acid polymer. The oral dosage formcan be in the form of an enteric coated compressed tablet made ofgranules or particles of active ingredient or a gelatin capsule whichcontains beads or small particles of active ingredient which havethemselves been enterically coated.

Any enteric coating which is insoluble at a pH below 5.5 (i.e., thatgenerally found in the mouth, pharynx, esophagus, and stomach), butsoluble at pH 5.5 or higher (i.e., that present in the small intestineand the large intestine) can be used in the practice of the presentinvention. Accordingly, when it is desired to effect delivery of thebisphosphonate and the chelating agent to the small intestine, anyenteric coating is suitable which is wholly- or partially-insoluble at apH below 5.5 and soluble at a pH 5.5 or above.

The enteric coating must be applied to the compressed tablet, thecapsule (e.g., gelatin, starch, or hydroxypropylmethylcellulose) and/orthe beads, particles or granules of active ingredient in a sufficientthickness so that the entire coating does not dissolve ingastrointestinal fluids at a pH below 5.5, but does dissolve at a pH of5.5 or above. The dissolution or disintegration of the excipient coatinggenerally does not occur until the entry of the coated dosage form intothe small intestine.

It is expected that any anionic polymer exhibiting the requisitepH-dependent solubility profile can be used as an enteric coating in thepractice of the present invention to achieve delivery of thebisphosphonate and chelating agent to the lower GI tract. The coatingchosen must be compatible with the particular bisphosphonate activeingredient selected. The preferred polymers for use in the presentinvention are anionic carboxylic polymers. It is particularly preferredthat the polymers are acrylic polymers, more preferably partlymethyl-esterified methacrylic acid polymers, in which the ratio of freeanionic carboxyl groups to ester groups is about 1:1.

A particularly suitable methacrylic acid copolymer is Eudragit L®,particularly Eudragit L 30 D-55® and Eudragit L 100-55®, manufactured byRöhm Pharma GmbH and Co. KG, Darmstadt, Germany. In Eudragit L 30 D-55®,the ratio of free carboxyl groups to ester groups is approximately 1:1.Further, said copolymer is known to be insoluble in GI fluids having apH below 5.5, generally 1.5-5.5, i.e., that generally present in thefluid of the upper GI tract, but readily soluble at pH above 5.5, i.e.,that generally present in the fluid of the lower GI tract.

Other methacrylic acid copolymer which are suitable for use in coatingthe oral dosage forms and/or the granules, particles, or beads of activeingredient which can be employed in the method of treatment describedherein, either alone or in combination with other coatings, is EudragitS® and Eudragit FS30D®, manufactured by Rohm Pharma GmbH and Co. KG,Darmstadt, Germany. Eudragit S® differs from Eudragit L 30 D-55®, onlyinsofar as the ratio of free carboxyl groups to ester groups isapproximately 1:2. Eudragit S® is also, like Eudragit L 30 D-55®,substantially insoluble at pH below 5.5, but unlike Eudragit L 30 D-55®,is poorly soluble in GI fluids having a pH of 5.5-7.0, such as thatpresent in small intestinal fluids. Eudragit S® is soluble at pH 7.0 andabove, i.e., that generally present in the terminal ileum and colon.

Eudragit S® can also be used alone as a coating which would providedelivery of the bisphosphonate active ingredient beginning primarily atthe large intestine (more distal than the terminal ileum) via adelayed-release mechanism. In addition, Eudragit S®, being poorlysoluble in intestinal fluids below pH 7.0, could be used in combinationwith Eudragit L 30 D-55®, soluble in intestinal fluids above pH 5.5, inorder to effect a delayed release composition which could be formulatedto deliver the active ingredient at various segments of the intestinaltract; the more Eudragit L 30 D-55® used, the more proximal release anddelivery begins and the more Eudragit S® used, the more distal releaseand delivery begins.

The coating can, and usually will, contain a plasticizer and possiblyother coating excipients such as coloring agents, surfactant, talc,and/or magnesium stearate, many of which are well known in the coatingart. In particular, anionic carboxylic acrylic polymers usually willcontain 10-25% by weight of a plasticizer, especially triethyl citrate,tributyl citrate, acteyltriethyl citrate, dibutyl phthalate, diethylphthalate, polyethylene glycol, acetylated monoglycerides propyleneglycol, and triacetin. Conventional coating techniques such as fluid-bedor pan coating are employed to apply the coating. Coating thickness mustbe sufficient to ensure that the oral dosage form remains essentiallyintact until the desired site of delivery in the lower GI tract isreached.

The solid oral dosage form may be in the form of a coated compressedtablet which contains particles or granules of the bisphosphonate activeingredient and the chelating agent, or of a soft or hard capsule (e.g.,gelatin, starch, or hydroxypropylmethylcellulose), coated or uncoated,which contains beads or particles of the bisphosphonate activeingredient and the chelating agent, which themselves are entericallycoated.

For sustained release of the bisphosphonate and chelating agent asustained release polymer is required to control the dissolution rate ofthe bisphosphonate and chelating agent from the dosage form. If thebisphosphonate and chelating agent are both soluble (defined as 33 mg/mlor greater in water) then high levels of sustained release polymers arerequired. Sustained release polymers include but are not limited tohydroxypropylmethycellulose, hydroxypropylcellulose and Carbomer.

A. Enteric Coated Tablets

In one embodiment of the invention, the oral dosage form includes anenteric-coated compressed tablet. Tablets are made by combining, mixing,or otherwise adding the bisphosphonate active ingredient and thechelating agent to suitable pharmaceutical excipients including, but notlimited to, sucrose, maltodextrin, lactose, cellulose, microcrystallinecellulose, talc, magnesium stearate, crospovidone, starch, and sodiumstarch glycolate. That mixture is then compressed into a tabletutilizing various methods known to those skilled in the art. Thecompressed tablet is then coated with an enteric-coating material whichis made with suitable pharmaceutical excipients including, but notlimited to, poly(methacrylic acid, methyl methacrylate 1:1 (Eudragit L®100), poly(methyacrylic acid, ethyl acrylate 1:1 (Eudragit L 30 D-55®,Eudragit L 100-55®), poly(methacrylic acid, methyl methacrylate 1:2(Eudragit S®, Eudragit F530D®), hydroxypropylmethylcellulose phthalate,cellulose acetate phthalate, polyvinyl acetate phthalate, shellac,cellulose acetate succinate, cellulose acetate trimellatate,polyethylene glycol 400-8000, triacetin, dibutyl phthalate, acetylatedmonoglycerides, triethyl citrate, talc, and iron oxide. Theenteric-coating material is then applied to the compressed tabletutilizing numerous spraying techniques available to those skilled in theart.

The enteric-coating of the tablets is not soluble in the fluids of themouth, pharynx, esophagus, or stomach, and thereby prohibits the releaseof the bisphosphonate and the EDTA until oral dosage form reaches thelower GI tract. For the coating method described herein usingmethacrylate copolymers, when the desired site of delivery is the lowerGI tract, it has been found that a coating thickness of between about 10and about 500 microns usually is required. In one embodiment of theinvention, the thickness is between about 10-30 and about 50 microns. Inanother embodiment, the thickness is between about 200 and about 350microns. Another way to characterize the coating is to express theamount of coating as weight gain or coating solids relative to theoriginal tablet weight. In one embodiment of the invention the weightgain of coating solids is 5-50% of the original tablet weight, inanother embodiment the coating solids weight gain is 5-15%, in yetanother embodiment it is 15-30% and in another it is 30-50%

B. Enteric-Coated Beads or Granules

Another oral dosage form suitable for use in the present inventionconsists of gelatin or starch capsules which contain enteric-coatedbeads or granules of the active ingredient. The gelatin or starchcapsules may themselves be enteric-coated, if desired. The use ofcapsules which contain enteric coated beads is generally not preferredfrom a standpoint of manufacturing cost and difficulty. However, someactive ingredients which must be given in relatively higher doses aresometimes difficult to compress into tablets. In addition, when ingestedwith food, tablets often sit in the stomach until the digestion of foodcauses the opening of the pyloric sphincter and pushes the tablet intothe duodenum. When uncoated gelatin or starch capsules are used, thegelatin or starch will break down in the stomach, releasing the entericcoated beads. The beads can travel through the pylorus independently ofthe presence of food, and there is decreased risk of large amounts ofthe active ingredient sitting for any period of time in direct contactwith the epithelial and mucosal tissues. As used herein, “beads” refersto particles containing the active ingredient which are prepared byapplying the bisphosphonate active ingredient and the chelating agent toinert substrate spheres, or beads, preferably using a polymer film.

The substrate bead, accordingly, is used as an inert substrate to whichthe bisphosphonate and the chelating agent are applied. The beads may bemade from one, or a mixture of, a group selected from, but not limitedto, sucrose, mannitol, lactose, dextrose, sorbitol, cellulose, andstarch, preferably sucrose and starch. In one embodiment of theinvention, the size of the inert substrate beads is in the range of from0.25 mm to 7.00 mm, preferably from 1.00 mm to 4.00 mm. In addition,suitable inert substrate beads may be purchased, as pre-prepared, forexample, non-pareil PG beads, manufactured by Penwest, Patterson, N.Y.

The bisphosphonate active ingredient and the chelating agent must beaffixed to the inert substrate beads. In one embodiment, the activeingredient and the chelating agent are affixed using a polymer film. Inaddition, if an active ingredient is chosen that is deliquescent, thepolymer film will serve to prevent the active from picking up moisture.If the active ingredient chosen is unstable in any way, the polymer filmmay provide some stability. The polymer film preferably comprises amixture of hydroxypropylmethylcellulose, ethylcellulose,polyvinylpyrrolidone, and/or hydroxypropylcellulose; and a suitableplasticizer. Plasticizers suitable for use in the film include, but arenot limited to, polyethylene glycol, propylene glycol, triacetin,acetylated monoglycerides, phthalate esters, castor oil, dibutylsecabate, triethyl citrate, and selected mixtures thereof. In oneembodiment, the plasticizer comprises from 5% to 40% of the polymerfilm, preferably from 10% to 25% of the polymer film.

The polymer film may further comprise optional fillers, pigments, anddyes as described hereinabove.

The polymer or polymer mix can include any combination that offersprotection against moisture pickup and/or oxygen transfer, and which isdesigned for immediate release of the active ingredient by intestinalfluid. The amount of bisphosphonate to be applied to the inert substratebeads may vary depending on the concentration desired in the finishedproduct. However, the weight of the applied film on the substrate beadis between about 5-50% weight gain, preferably between 5-25% weightgain. The term “weight gain,” as used herein, means the weight increaseas a percentage of the amount of applied solids to the substrate.

After the inert substrate beads are coated with the active ingredientand chelating agent, they must be enterically coated. The entericcoating is applied using various spray techniques known to one skilledin the art. The coating is applied to the beads of active ingredient ata thickness of about 20-350 microns, in another embodiment about 30-100microns. The coating amount can be characterized as a weight gain ofabout 10-75%, in other cases about 20-50% relative to the originalweight of the beads.

It may be desired to coat the granules of the bisphosphonate activeingredient and the chelating agent instead of spraying inert substratebeads with the bisphosphonate and the chelating agent. “Granules,” asused herein, means particles of active ingredient and chelating agent incombination with suitable pharmaceutically-acceptable excipients asdescribed hereinabove. Although it is preferable to encapsulate theenteric-coated granules using starch or gelatin capsules, foradministration as an oral dosage form, the granules may also becompressed into tablets.

Granules can be obtained by extrusion of a moist kneaded mass followedby spheronization and drying. Granules with a regular molding arepreferred, for example, rod-shaped, cylindrical, or spherical. In oneembodiment, the granules are spherical pellet-type granules, with adiameter between about 0.3 and about 1.5 mm, preferably between about0.5 and about 1.25 mm.

Suitable pharmaceutically-acceptable excipients for making the granulesto be used in the novel dosage forms described herein include, but arenot limited to, lactose, mannitol, cellulose, sucrose, and starch.

The prepared granules of active ingredient and chelating agent are thencoated with an enteric coating material prepared from thepharmaceutically-acceptable excipients, using various coating techniquesknown to those skilled in the art. The coating is applied to thegranules at a thickness of about 20-350 microns, preferably about 30-100microns. The coating amount can be characterized as a weight gain ofabout 10-75%, preferably about 20-50% relative to the original weight ofthe beads.

Bacterial Enzyme Triggered Systems

In one embodiment of the invention, delivery of the bisphosphonate andthe chelating agent to the lower GI tract is achieved through the use ofa bacterial enzyme triggered system. Oral dosage forms from which drugrelease is triggered by the action of bacterial enzymes in the colon areknown in the art. Various approaches to bacterially-triggered deliverysystems suitable for use in the present invention include disulfidepolymers, glycosidic prodrugs, and polysaccharides as matrices/coatingagents. Watts, Peter J. & Illum, Lisbeth, Drug Dev. and Indus. Pharm.,23(9): 893-917 (1997).

Further approaches to bacterially-triggered delivery systems suitablefor use are disclosed in Katsuma et al., J. of Pharm. Sci. 93(5):1287-99 (2004). In one embodiment of the invention, the colon-targeteddelivery system CODES™ (Yamanouchi Pharma Technologies, Norman, Okla.)is used to deliver the bisphosphonate and the chelating agent to thecolon. This system comprises a tablet core containing a bisphosphonate,a chelating agent, and a saccharide, which tablet core is coated with anacid soluble material, such as Eudragit E®, and then coated with anenteric coating, such as Eudragit L®. The enteric coating protects thedosage form from degradation in the stomach, and is subsequentlydissolved in the small intestine following gastric emptying. Theacid-soluble coating protects against degradation as the dosage formtravels through the small intestine. When the dosage form reaches thelarge intestine, local microflora ferment the saccharide in the tabletcore into short chain fatty acids, which then dissolve the acid-solublecoating to release the core tablet contents in the colon.

Suitable enteric coating materials include Eudragit L-100®, Eudragit S®,Eudragit L 30 D-55®, Eudragit F530D® cellulose acetate phthalate,shellac, or any enteric coating material that dissolves above pH 5.5.The enteric coating is applied using various spray techniques known toone skilled in the art. The enteric coating may further comprise one ormore pharmaceutically-acceptable excipients including, but not limitedto, talc, triethyl citrate, polyethylene glycol, Tween 80®(polyoxyethylene sorbitan monooleate, available from Sigma Chemical CO.,St. Louis, Mo.), castor oil. The enteric coating is applied to thetablet core coated in acid-soluble material to provide a weight gain of2.5% to 40%.

Suitable acid-soluble coating materials include those materials whichdissolve at a pH less than 6.0, including but not limited to EudragitE-100®, polyvinyl acetyl diethylaminoacetate, and chitosan. Theacid-soluble coating may further comprise one or morepharmaceutically-acceptable excipients. Such excipients include, but arenot limited to, hydroxypropylmethylcellulose, Eudragit RS®,ethylcellulose, hydroxypropylcellulose, polyethylene oxide,polyvinylpyrrolidone, triacetin, polyethylene glycol 400,triethylcitrate, Tween 80®, and castor oil. The acid-soluble coating isapplied using various spray techniques known to one skilled in the art.The coating is applied to the tablet core at a weight gain of 2.5% to40%.

The tablet core comprises one or more saccharide in an amount of 10% to99.9% by weight of the tablet. The action of enterobacteria in the lowerGI tract causes the saccharide(s) to be degraded into shorter chainfatty acids, which then dissolve the acid-soluble coating. Suitablesaccharides include, but are not limited to, lactulose, raffinose,cellobiosc, stachyose, fructoligosaccharide, sucrose, glucose, xylose,fructose, maltose, galactose cellulosic, and combinations thereof.

The tablet core comprises a bisphosphonate active ingredient, achelating agent, and may contain one or more pharmaceutically-acceptableexcipients. Suitable excipients include, but are not limited to,crystalline cellulose, calcium hydrogen phosphate, polyvinylpyrrolidone,magnesium stearate, sucrose, starch, magnesium oxide, and sodium laurylsulfate.

Time Dependent Delivery Systems

In another embodiment of the invention, delivery of the bisphosphonateand the chelating agent to the lower GI tract is achieved through theuse of a time dependent delivery system. Given established transit timesafter gastric emptying, drug and/or chelating agent release can betargeted to the various segments of the lower GI tract. For example, inorder to target release of the bisphosphonate active ingredient and thechelating agent to the colon, release should be delayed until 3-4 hoursafter leaving the stomach. Watts, Peter J. & Illum, Lisbeth, Drug Dev.and Indus. Pharm., 23(9): 893-917 (1997). Approaches to time dependentdelivery systems suitable for use in the present invention include, butare not limited to, such devices as the Pulsincap™ (Scherer DDS,Strathclyde, U.K.), the Time Clock™ (Zambon Group, Milan, Italy), andSyncroDose™ (Penwest, Patterson, N.Y.), as well as various coatingswhich degrade over time to release tablet contents such ashydroxypropylmethylcellulose, hydroxypropylcellulose, or any suitablehydrogel.

In one embodiment of the invention, the time-dependent device Pulsincap™is used to target delivery of the active ingredient and the chelatingagent to the lower GI tract. The active ingredient and other excipients,including the chelating agent, are contained inside the Pulsincap™water-insoluble capsule by means of a hydrogel plug which is covered bya water-soluble cap. The entire dose form is optionally coated in anenteric-coating material to protect the dose form from degradation whilein transit through the upper GI tract. When the patient swallows thePulsincap™ dosage form, the water-soluble cap dissolves and exposes thehydrogel plug to gastric and/or intestinal fluids. The hydrogel cap thenswells, and eventually pops out of the capsule body, thus releasing thecapsule contents. Release of the capsule contents can be targeted tospecific regions of the lower GI tract by modifying the hydrogel plugproperties. Watts, Peter J. & Illum, Lisbeth, Drug Dev. and Indus.Pharm., 23(9): 893-917 (1997).

In one embodiment of the invention, a time dependent coating is appliedover a compressed tablet and then an enteric coating is applied over thetime dependent coating. This is used to target delivery of the activeingredient and the chelating agent to the lower GI tract. The activeingredient and other excipients, including the chelating agent, arecontained inside the core tablet. The entire dose form is coated with atime dependent coating and then an enteric coating. The enteric-coatingmaterial is to protect the dose form from degradation while in transitthrough the upper GI tract. When the patient swallows the dosage formthe enteric coating dissolves after the dosage form leaves the stomachand then the core tablet starts to swell. Eventually, at a predeterminedtime in the lower GI tract fluids, the time dependent coating willrupture and releases the contents of the core tablet in the lower GItract. Release of the core tablet contents can be targeted to specificregions of the lower GI tract by modifying the core tablet, timedependent coating and/or the enteric coating.

Pharmaceutically-Acceptable Excipients

Pharmaceutically-acceptable excipients include, but are not limited to,polymers, resins, plasticizers, fillers, lubricants, diluents, binders,disintegrants, solvents, co-solvents, surfactants, buffer systems,preservatives, sweetener agents, flavoring agents, pharmaceutical-gradedyes or pigments, chelating agents, viscosity agents, and combinationsthereof. Pharmaceutically-acceptable excipients can be used in anycomponent in making the oral dosage form, i.e. core tablet or coating.

Flavoring agents and dyes and pigments among those useful herein includebut are not limited to those described in Handbook of PharmaceuticalExcipients (4th Ed., Pharmaceutical Press 2003).

Suitable co-solvents include, but are not limited to, ethanol,isopropanol, and acetone.

Suitable surfactants include, but are not limited to, polyoxyethylenesorbitan fatty acid esters, polyoxyethylene monoalkyl ethers, sucrosemonoesters, simethicone emulsion, sodium lauryl sulfate, Tween 80®, andlanolin esters and ethers.

Suitable preservatives include, but are not limited to, phenol, alkylesters of parahydroxybenzoic acid, benzoic acid and the salts thereof,boric acid and the salts thereof, sorbic acid and the salts thereof,chlorbutanol, benzyl alcohol, thimerosal, phenylmercuric acetate andnitrate, nitromersol, benzalkonium chloride, cetylpyridinium chloride,methyl paraben, and propyl paraben.

Suitable fillers include, but are not limited to, starch, lactose,sucrose, maltodextrin, and microcrystalline cellulose.

Suitable plasticizers include, but are not limited to, triethyl citrate,polyethylene glycol, propylene glycol, dibutyl phthalate, castor oil,acetylated monoglycerides, and triacetin.

Suitable polymers include, but are not limited to, ethylcellulose,cellulose acetate trimellitate, hydroxypropylmethylcellulose phthalate,cellulose acetate phthalate, polyvinyl acetate phthalate, and Eudragit®L 30-D, Eudragit® L 100-55, Eudragit® F530D and Eudragit® S 100 (RöhmPharma GmbH and Co. KG, Darmstadt, Germany), and Acryl-EZE® andSureteric® (Colorcon, Inc., West Point, Pa.).

Suitable lubricants include, but are not limited to, magnesium stearate,stearic acid, and talc.

Methods of Use

The present invention further relates to a method of treating orpreventing diseases characterized by abnormal calcium and phosphatemetabolism comprising administering to a human or other mammal in needthereof a safe and effective amount of a pharmaceutical compositiondelivered to said human or other mammal via the oral dosage formsdescribed herein.

Diseases characterized by abnormal calcium and phosphate metabolisminclude, but are not limited to, osteoporosis, Paget's disease (osteitisdeformans), hyperparathyroidism, hypercalcemia of malignancy, osteolyticbone metastasis, myositis ossificans progressiva, calcinosisuniversalis, and such afflictions as arthritis, neuritis, bursitis,tendonitis, and other inflammatory conditions which predispose involvedtissue to deposition of calcium phosphates.

The oral dosage forms of the present invention are suitable foradministration to a patient according to a continuous dosing interval ofdaily, weekly, three times per month, twice monthly, and monthly.

Kits

The present invention further comprises kits that are particularlyuseful for administering the oral dosage forms described hereinaccording to a continuous dosing schedule of daily, weekly, three timesper month, twice monthly, or monthly. Such kits comprise one or moreoral dosage forms comprising a bisphosphonate and a chelating agent anda means for facilitating compliance with methods of this invention. Suchkits provide a convenient and effective means for assuring that thesubject to be treated takes the appropriate oral dosage form in thecorrect dosage and in the correct manner. The compliance means of suchkits includes any means which facilitates administering the activeaccording to a method of this invention. Such compliance means includesinstructions, packaging, and dispensing means, and combinations thereof.The kits can also comprise a means for aiding the memory, including butnot limited to a listing of the days of the week, numbering,illustrations, arrows, Braille, calendar stickers, reminder cards, orother means specifically selected by the patient. Examples of packagingand dispensing means are well known in the art, including thosedescribed in U.S. Pat. No. 4,761,406, Flora et al., issued Aug. 2, 1988;and U.S. Pat. No. 4,812,311, Uchtman, issued Mar. 14, 1989.

Optionally, the kits can comprise at least one oral dosage formcomprising a bisphosphonate and a chelating agent and at least one oraldosage form of an accompanying nutrient. Preferred nutrients are calciumand/or vitamin D. Oral forms of calcium suitable for use in the presentinvention include capsules, compressed tablets, chewable tablets, andthe like. Typical salt forms of calcium suitable for use in the presentinvention include but are not limited to calcium carbonate, calciumcitrate, calcium malate, calcium citrate malate, calcium glubionate,calcium gluceptate, calcium gluconate, calcium lactate, dibasic calciumphosphate, and tribasic calcium phosphate. In one embodiment, kits ofthe present invention may include tablets comprising 400 mg to 1500 mgcalcium.

The term “vitamin D,” as used herein, refers to any form of vitamin Dthat may be administered to a mammal as a nutrient. Vitamin D ismetabolized in the body to provide what is often referred to as“activated” forms of vitamin D. The term “vitamin D” can includeactivated and non-activated forms of vitamin D, as well as precursorsand metabolites of such forms. Precursors of these activated formsinclude vitamin D₂ (ergocalciferol, produced in plants) and vitamin D₃(cholecalciferol, produced in skin and found in animal sources and usedto fortify foods). Vitamins D₂ and D₃ have similar biological efficacyin humans. Non-activated metabolites of vitamins D₂ and D₃ includehydroxylated forms of vitamins D₂ and D₃. Activated vitamin D analogscannot be administered in large doses on an intermittent schedule, dueto their toxicity in mammals. However, non-activated vitamin D₂, vitaminD₃, and their metabolites may be administered in larger doses than“active” forms of vitamin D on an intermittent basis, without toxicity.In one embodiment, kits of the present invention may include tabletscomprising 100 IU to 10,000 IU of vitamin D.

In another embodiment, kits of the present invention may include one ormore nutrient tablets comprising both calcium and vitamin D. In afurther embodiment, the unit dose of nutrient comprises about 600 mgcalcium and about 400 IU vitamin D.

The following non-limiting examples illustrate the formulations,processes, and uses of the present invention.

EXAMPLES Example I Enteric-Coated Tablets Containing Risedronate andEDTA

Enteric-coated tablets containing risedronate and EDTA are made bypreparing a coating composition and compressed tablets containingrisedronate and EDTA, and then applying said coating composition to saidtablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Ingredients:

Eudragit L 30 D-55 ® (wet basis) 143.3 mg  (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethylcitrate 6.45 mg Talc 21.5mg Red Iron Oxide 0.22 mg Simethicone emulsion (30%) 0.43 mg Polysorbate80 0.43 mg Purified Water 307.7 mg 

The enteric coating is prepared using the following method:

A pigment suspension is prepared by adding polysorbate 80, ground ferricoxide, and talc to approximately two-thirds of the purified water whilemixing. The suspension is mixed for at least two hours. The 30%simethicone emulsion and the remaining water are added to the pigmentsuspension and mixed for at least 45 minutes. The Eudragit L 30 D-55solution and triethyl citrate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process. The core tablets aretransferred to the coating pan and preheated with occasional jogging.Tablets are coated, using a typical pan coating process until therequired quantity of coating solution has been applied. Tablets are thencooled and collected in suitable containers.

A coating weight gain of 30% (total solids) is applied by spraying theabove composition onto compressed tablets containing risedronate andEDTA, prepared in Part B below.

B. Compressed Tablets Containing Risedronate and EDTA

The enteric coating suspension prepared in Part A above is sprayed onto35 mg risedronate tablets, each tablet weighing 240 mg and eachcontaining:

Active Ingredients:

Risedronate Sodium 35 mg* Chelant: Disodium EDTA 100 mg Excipients:Microcrystalline cellulose 85.8 mg Sodium starch glycolate 6 mg Stearicacid 12 mg Magnesium stearate 1.2 mg *This amount is calculated on arisedronate anhydrous monosodium salt basis.

Tablets having the composition set forth above are prepared as follows:

The risedronate sodium, edetate disodium, sodium starch glycolate, andmicrocrystalline cellulose are passed through a mill and added to ablender equipped with an intensifier bar. The mixture is blended forapproximately ten minutes with the intensifier bar on. The stearic acidand magnesium stearate are screened and added to the blender. The blendis mixed for approximately 3 minutes with the intensifier bar off. Theblend is compressed into tablets using a suitable tablet press.

Example II Enteric-Coated Tablets Containing Risedronate and EDTA

Enteric-coated tablets containing risedronate sodium are prepared asdescribed below, using a similar method set forth in Example I.

A coating composition is prepared from a lacquer containing thefollowing excipients, per tablet:

Ingredients:

Acryl-EZE (manufactured by 200 mg Colorcon, 200 mg Inc., West Point,Pa.) dry solids Purified Water 950 mg

A coating weight of 40% weight gain is applied by conventional pancoating to tablets containing 150 mg risedronate and 75 mg EDTA so thatoval tablets, each weighing 500 mg, result. The composition of eachtablet is as follows:

Active Ingredients:

Risedronate Sodium 150 mg* Chelant: Disodium EDTA 75 mg Excipients:Mannitol 100 mg Starch 1500 159 mg Silicon Dioxide 1 mg Stearic acid 15mg *This amount is calculated on a risedronate anhydrous monosodium saltbasis.

Example III Enteric-Coated Tablets Containing Risedronate and EDTA

Enteric-coated tablets containing risedronate and EDTA are made bypreparing a coating composition and compressed tablets containingrisedronate and EDTA, and then applying said coating composition to saidtablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Ingredients:

Eudragit L 30 D-55 ® (wet basis) 47.8 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethylcitrate 2.15 mg Talc 7.17mg Red Iron Oxide 0.07 mg Simethicone emulsion (30%) 0.14 mg Polysorbate80 0.14 mg Purified Water 102.6 mg

The enteric coating is prepared using the following method:

A pigment suspension is prepared by adding polysorbate 80, ground ferricoxide, and talc to approximately two-thirds of the purified water whilemixing. The suspension is mixed for at least two hours. The 30%simethicone emulsion and the remaining water are added to the pigmentsuspension and mixed for at least 45 minutes. The Eudragit L 30 D-55solution and triethyl citrate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process. The core tablets aretransferred to the coating pan and preheated with occasional jogging.Tablets are coated, using a typical pan coating process until therequired quantity of coating solution has been applied. Tablets are thencooled and collected in suitable containers.

A coating weight gain of 10% (total solids) is applied by spraying theabove composition onto compressed tablets containing risedronate andEDTA, prepared in Part B below.

B. Compressed Tablets Containing Risedronate and EDTA

The enteric coating suspension prepared in Part A above is sprayed onto35 mg risedronate tablets, each tablet weighing 230 mg and eachcontaining:

Active Ingredients:

Risedronate Sodium 35 mg* Chelant: Disodium EDTA 100 mg Excipients:Microcrystalline cellulose 25.8 mg Hypromellose 76.8 mg Magnesiumstearate 2.4 mg *This amount is calculated on a risedronate anhydrousmonosodium salt basis.

Tablets having the composition set forth above are prepared as follows:

The risedronate sodium, edetate disodium, hypromellose, andmicrocrystalline cellulose are passed through a mill and added to ablender equipped with an intensifier bar. The mixture is blended forapproximately twenty minutes with the intensifier bar on. Approximately50% of the magnesium stearate is screened and added to the blender. Theblend is mixed for approximately 3 minutes with the intensifier bar offand then chilsonated and milled. The remaining magnesium stearate isscreened and added to the blender with the granulation. The blend ismixed for approximately 3 minutes with the intensifier bar off. Theblend is compressed into tablets using a suitable tablet press.

Example IV Enteric-Coated Tablets Containing Risedronate and EDTA

Enteric-coated tablets containing risedronate and EDTA are made bypreparing a coating composition and compressed tablets containingrisedronate and EDTA, and then applying said coating composition to saidtablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Ingredients:

Eudragit L 30 D-55 ® (wet basis) 150 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethylcitrate 10 mg Talc 30 mgBlack Iron Oxide 0.1 mg Purified Water 250 mg

The enteric coating is prepared using the following method:

The talc and black iron oxide are added to a portion of purified waterand mixed until uniform. The triethylcitrate is added with continuousmixing. The resulting pigment suspension is next passed through a screenor a suitable mill to break up agglomerates. The Eudragit L 30 D-55® isscreened and then added to a suitable vessel and diluted with a portionof the purified water. The pigment suspension is then added to thediluted Eudragit suspension and mixed until uniform.

In a suitable coating pan, the compressed tablets (10 kg) containingrisedronate and EDTA, described below, are warmed to about 30-35° C. Theenteric coating suspension is sprayed onto the tablets at approximately30 grams per minute. When the spray cycle is completed, the temperatureis reduced and the tablets are removed and dried at 30-35° C. forapproximately 1 hour.

A coating weight gain of 35% (total solids) is applied by spraying theabove composition onto compressed tablets containing risedronate andEDTA, prepared in Part B below.

B. Compressed Tablets Containing Risedronate and EDTA

The enteric coating suspension prepared in Part A above is sprayed onto5 mg risedronate tablets, each tablet weighing 240 mg and eachcontaining:

Active Ingredients:

Risedronate sodium 5.0 mg* Chelant: Disodium EDTA 75.0 mg Excipients:Microcrystalline cellulose 149.5 mg Sodium starch glycolate 9 mg Stearicacid 1.5 mg *This amount is calculated on a risedronate anhydrousmonosodium salt basis.

Tablets having the composition set forth above are prepared as follows:

The tablets are prepared by sieving the risedronate active ingredientand the EDTA with ½ of the microcrystalline cellulose into a twin shellblender. The blend is then mixed until uniform. Then, ½ of the stearicacid is added and the blend is mixed further. The blend is then rollercompacted and milled. The remaining microcrystalline cellulose andsodium starch glycolate are added and mixed until uniform. The remainingstearic acid is then added and mixed until adequate lubrication isachieved. Tablets are then compressed on a rotary tablet press.

Example V Capsules Containing Enteric-Coated Particles

Capsules containing enteric-coated particles are made by preparingparticles of the risedronate sodium active ingredients and EDTA, andthen encapsulating them into a gelatin capsule. The particles have thefollowing composition:

Component mg/capsule Active Ingredients: Risedronate Sodium  35 mg*Chelant: EDTA 75 mg Excipients: Lactose 50 mg Microcrystalline Cellulose50 mg *This amount is calculated on a risedronate anhydrous monosodiumsalt basis.

A mixture of risedronate sodium, EDTA, lactose, and microcrystallinecellulose is moistened with water and kneaded, extruded, andspheronized. The dried particles are subsequently coated with entericcoating material prepared as described in Example XIII.

The enteric coating has the following composition:

Component mg/capsule Eudragit L 30 D-55 ® 90 Triethylcitrate 6 AntifoamAF 2 Talc 7 Water 275

The particles having the composition described above are coated in acoating column with a coating mixture having the above composition.

The enteric coating is prepared utilizing the procedure set forth inExample XIII. In a suitable coating column, the particles are warmed toabout 25° C. and enteric coating solution is applied to the particles byspraying a coating of 20% weight gain to the particles. When the spraycycle is completed, the air is turned off and the particles are cooledto room temperature.

The lacquered particles are powdered with talc and encapsulated usingcapsules (capsule size 0), with a commercial capsule filling machine.

Example VI Bacterial Enzyme Triggered Tablets Containing Risedronate andSodium Hexametaphosphate

Bacterial enzyme triggered tablets containing risedronate and sodiumhexametaphosphate are made by preparing a two layer coating compositionand compressed tablets containing risedronate and sodiumhexametaphospahte and then applying said coating composition to saidtablets.

The first layer (Acid Soluble Coating Layer) coating composition isprepared in the form of a lacquer containing the following excipients,per tablet:

A. Acid Soluble Coating Layer Ingredients:

Eudragit E 100 ® 40.0 mg (manufactured by Röhm Pharma GmbH and Co. KG,Darmstadt, Germany) Hydroxypropylmethylcellulose 10 mg Talc 10 mgEthanol 450 mL Purified Water 50 mL

The acid soluble coating is prepared using the following method:

A talc suspension is prepared by adding talc to approximately one-thirdof the purified water while mixing. The suspension is mixed for at leasttwo hours. The Eudragit E 100® and hydroxyproylmethylcelluse are addedto the remaining water and ethanol mixture and mixed until dissolved.The talc suspension is then added to the Eudragit solution and mixed for30 to 60 minutes. The resulting coating suspension is screened and mixedthroughout the coating process.

B. Enteric Coating Suspension (Second Layer) Ingredients:

Eudragit L 30 D-55 ® (wet basis) 150 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethyl citrate 6.0 mg Talc 15.0mg Red Iron Oxide 0.25 mg Purified Water 260 mg

The enteric coating is prepared using the following method:

A pigment suspension is prepared by adding ground ferric oxide, and talcto approximately two-thirds of the purified water while mixing. Thesuspension is mixed for at least two hours. The Eudragit L 30 D-55solution and triethyl citrate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process.

The compressed tablets as described below are transferred to the coatingpan and preheated with occasional jogging. The compressed tablets arecoated with the Acid Soluble Coating then with the Enteric CoatingSuspension using a typical pan coating process until the requiredquantity of coating solution has been applied. Tablets are then cooledand collected in suitable containers.

A coating weight gain of 12% for the Acid Soluble Coating and 13% forthe Enteric Coating (total solids compared to that of the core tabletweight) is applied by spraying the above composition (A and B) ontocompressed tablets containing risedronate and sodium hexametaphosphateprepared in Part C below.

C. Compressed Tablets Containing Risedronate and SodiumHexametaphosphate

The Acid Soluble Coating and the Enteric Coating suspension prepared inPart A and B above is sprayed onto 35 mg risedronate tablets, eachtablet weighing 500 mg and each containing:

Active Ingredients:

Risedronate Sodium 35 mg* Chelant: Sodium hexametaphosphate 150 mgExcipients: Lactulose 300 mg Stearic acid 14.5 mg Magnesium stearate 0.5mg Purified Water 100.0 mg *This amount is calculated on a risedronateanhydrous monosodium salt basis.

Tablets having the composition set forth above are prepared as follows:

The risedronate sodium, sodium hexametaphosphate, lactulose and thestearic acid are passed through a mill and added to a blender equippedwith an intensifier bar. The mixture is blended for approximately tenminutes with the intensifier bar on and granulated with the purifedwater for 15 minutes. The mixture is dried overnight at 30° C., passedthrough a mill. The magnesium stearate is screened and added to theblender. The blend is mixed for approximately 3 minutes. The blend iscompressed into tablets using a suitable tablet press.

Example VII Time Dependent and Enteric Coated Tablets ContainingRisedronate and Sodium Citrate

Time Dependent and Enteric Tablets containing risedronate and sodiumcitrate are made by preparing a two layer coating composition andcompressed tablets containing risedronate and sodium citrate and thenapplying said coating composition to said tablets.

The first layer (Time Dependent Coating Layer) coating composition isprepared in the form of a polymer containing the following excipients,per tablet:

A. Acid Soluble Coating Layer Ingredients:

Ethylcellulose 40.0 mg Dibuty Sebacate 8 mg Toluene 250 mg Ethyl Alcohol70 mg

The acid soluble coating is prepared using the following method:

A solution is prepared by adding the ethylcellulose to approximatelytwo-thirds of the toluene:ethyl alcohol mixture while mixing. Thesolution is mixed for at least two hours. The dibuty sebacate is addedand mixed for an additional two hours. The resulting coating solution isscreened and mixed throughout the coating process.

B. Enteric Coating Suspension Ingredients:

Eudragit L 30 D-55 ® (wet basis) 150 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethyl citrate 6.0 mg Talc 15.0mg Red Iron Oxide 0.25 mg Purified Water 260 mg

The enteric coating is prepared using the following method:

A pigment suspension is prepared by adding ground ferric oxide, and talcto approximately two-thirds of the purified water while mixing. Thesuspension is mixed for at least two hours. The Eudragit L 30 D-55solution and triethyl citrate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process.

The compressed tablets are transferred to the coating pan and preheatedwith occasional jogging. The compressed tablets are coated with the TimeDependent Coating then with the Enteric Coating Suspension using atypical pan coating process until the required quantity of coatingsolution has been applied. Tablets are then cooled and collected insuitable containers.

A coating weight gain of 10% for the Time Dependent Coating and 13%Enteric Coating (total solids compared to that of the core tabletweight) is applied by spraying the above composition (A and B) ontocompressed tablets containing risedronate and sodium citrate prepared inPart C below.

C. Compressed Tablets Containing Risedronate and sodium citrate

The Acid Soluble Coating and the Enteric Coating suspension prepared inPart A and B above is sprayed onto 5 mg risedronate tablets, each tabletweighing 500 mg and each containing:

Active Ingredients:

Risedronate Sodium 5 mg* Chelant: Sodium Citrate 250 mg Excipient:Microcrystalline Cellulose 109.5 mg Croscarmellose Sodium 25.0 mgMannitol 100 mg Magnesium stearate 0.5 mg Polyvinylpyrrolidone 10 mgPurified Water 100.0 mg *This amount is calculated on a risedronateanhydrous monosodium salt basis.

Tablets having the composition set forth above are prepared as follows:

The risedronate sodium, sodium citrate, microcrystalline cellulose,croscarmellose sodium, mannitol and polyvinylpyrrolidone are passedthrough a mill and added to a blender equipped with an intensifier bar.The mixture is blended for approximately ten minutes with theintensifier bar on and granulated with purified water for 15 minutes.The mixture is dried overnight at 30° C., passed through a mill. Themagnesium stearate is screened and added to the blender. The blend ismixed for approximately 3 minutes with the intensifier bar off. Theblend is compressed into tablets using a suitable tablet press.

Example VIII Time Dependent Delivery Tablets Containing Risedronate andEDTA

Time dependent delivery tablets containing risedronate and EDTA are madeby preparing a coating composition and compressed tablets containingrisedronate and EDTA, and then applying said coating composition to saidtablets.

A coating composition is prepared containing the following excipients,per tablet:

A. Coating Suspension Excipients:

Carnauba Wax 80 mg Beeswax 35 mg Polyoxyethylene sorbitan monooleate 11mg Hydroxypropylmethylcellulose 24 mg Purified Water 500 mL

The coating is prepared using the following method:

The carnauba wax, beeswax, polyoxyethlyene sorbitan monooleate, andhydroxypropylmethylcellulose are added to the purified water at 60° C.and mixed for 3 hours. The resulting coating mixture is screened andmixed throughout the coating process. The core tablets are transferredto the coating pan and preheated with occasional jogging. Tablets arecoated, using a typical pan coating process until the required quantityof coating solution (at 60° C.) has been applied. Tablets are thencooled and collected in suitable containers.

A coating weight gain of 30% (total solids) is applied by spraying theabove composition onto compressed tablets containing risedronate andEDTA, prepared in Part B below.

B. Compressed Tablets Containing Risedronate and EDTA

The coating suspension prepared in Part A above is sprayed onto 35 mgrisedronate tablets, each tablet weighing 500 mg and each containing:

Active Ingredients:

Risedronate Sodium 35 mg* Chelant: Disodium EDTA 150 mg Excipients:Microcrystalline cellulose 50 mg Spray Dried Lactose 245 mg Sodiumstarch glycolate 15 mg Magnesium stearate 5 mg *This amount iscalculated on a risedronate anhydrous monosodium salt basis.

Tablets having the composition set forth above are prepared as follows:

The risedronate sodium, EDTA disodium, microcrystalline cellulose, Spraydried lactose and sodium starch glycolate are passed through a mill andadded to a blender equipped with an intensifier bar. The mixture isblended for approximately ten minutes with the intensifier bar on. Themagnesium stearate is screened and added to the blender. The blend ismixed for approximately 3 minutes with the intensifier bar off. Theblend is compressed into tablets using a suitable tablet press.

Example IX Bacterial Enzyme Triggered Tablets Containing Alendronate andTartaric Acid

Bacterial Enzyme Triggered tablets containing alendronate and tartaricacid are made by preparing a tablet blend and compressing into tablets.

A. Compressed Tablets Containing Alendronate and Tartaric Acid

The 70 mg alendronate, each tablet weighing 680 mg and each containing:

Active Ingredients:

Alendronate Sodium 70.0 mg* Excipients: Guar Gum 300.0 mgHydroxypropylmethylcellulose 50.0 mg Tartaric Acid 250.0 mg Stearic acid10 mg *This amount is calculated on a alendronic acid anhydroustrihydrate basis.

Tablets having the composition set forth above are prepared as follows:

The alendronate sodium, guar gum, hydroypropylmethylcellulose andtartaric acid are passed through a mill and added to a blender equippedwith an intensifier bar. The mixture is blended for approximately tenminutes with the intensifier bar on. The blend is compressed into slugson a rotary tablet press. The slugs are passed through a mill andcollected. The stearic acid is added to the blender and the blend ismixed for approximately 3 minutes. The blend is compressed into tabletsusing a suitable tablet press.

The compressed tablets are coated with the layers described in ExampleVI using the same methods for coating.

Example X Enteric-Coated Tablets Containing Alendronate and EDTA

Enteric-coated tablets containing alendronate and EDTA are made bypreparing a coating composition and compressed tablets containingalendronate and EDTA, and then applying said coating composition to saidtablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Excipients:

Eudragit L 30 D-55 ® (wet basis) 120 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethylcitrate 10 mg Talc 10 mgRed Iron Oxide 0.01 mg Simethicone emulsion 0.8 mg Purified Water 100 mg

The enteric coating is prepared using the following method:

The talc and red iron oxide are added to a portion of purified water andmixed until uniform. The triethylcitrate and the simethicone emulsionare added with continuous mixing. The resulting pigment suspension isnext passed through a screen or a suitable mill to break upagglomerates. The Eudragit L 30 D-55® is screened and then added to asuitable vessel and diluted with a portion of the purified water. Thepigment suspension is then added to the diluted Eudragit suspension andmixed until uniform.

In a suitable coating pan, the compressed tablets (10 kg) containingalendronate and EDTA, described below, are warmed to about 30-35° C. Theenteric coating suspension is sprayed onto the tablets at approximately30 grams per minute. When the spray cycle is completed, the temperatureis reduced and the tablets are removed and dried at 30-35° C. forapproximately 1 hour.

A coating weight gain of 19% (total solids) is applied by spraying theabove composition onto compressed tablets containing alendronate andEDTA, prepared in Part B below.

B. Compressed Tablets Containing Alendronate and EDTA

The enteric coating suspension prepared in Part A above is sprayed onto70 mg alendronate tablets, each tablet weighing 300 mg and eachcontaining:

Active Ingredients:

Alendronate sodium 70 mg* Chelant: Disodium EDTA 100 mg Excipients:Microcrystalline cellulose 119.5 mg Crospovidone 9 mg Magnesium stearate1.5 mg *This amount is calculated on an alendronic acid basis.

Tablets having the composition set forth above are prepared as follows:

The tablets are prepared by sieving the alendronate active ingredientand the EDTA with ½ of the microcrystalline cellulose into a twin shellblender. The blend is then mixed until uniform. Then, ½ of the magnesiumstearate is added and the blend is mixed further. The blend is then isroller compacted and milled. The remaining microcrystalline celluloseand crospovidone are added and mixed until uniform. The remainingmagnesium stearate is then added and mixed until adequate lubrication isachieved. Tablets are then compressed on a rotary tablet press.

Example XI Enteric-Coated Tablets Containing Ibandronate and Citric Acid

Enteric-coated tablets containing ibandronate and citric acid are madeby preparing a coating composition and compressed tablets containingibandronate and citric acid, and then applying said coating compositionto said tablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Excipients:

Eudragit L 30 D-55 ® (wet basis) 240 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethylcitrate 20 mg Talc 10 mgTitanium dioxide 1.0 mg Simethicone emulsion 1.6 mg Purified Water 250mg

The enteric coating is prepared using the following method:

The talc and titanium dioxide are added to a portion of purified waterand mixed until uniform. The triethylcitrate and the simethiconeemulsion are added with continuous mixing. The resulting pigmentsuspension is next passed through a screen or a suitable mill to breakup agglomerates. The Eudragit L 30 D-55® is screened and then added to asuitable vessel and diluted with a portion of the purified water. Thepigment suspension is then added to the diluted Eudragit suspension andmixed until uniform.

In a suitable coating pan, the compressed tablets (10 kg) containingibandronate and Citric Acid, described below, are warmed to about 30-35°C. The enteric coating suspension is sprayed onto the tablets atapproximately 30 grams per minute. When the spray cycle is completed,the temperature is reduced and the tablets are removed and dried at30-35° C. for approximately 1 hour.

A coating weight gain of 17% (total solids) is applied by spraying theabove composition onto compressed tablets containing Ibandronate andcitric acid, prepared in Part B below.

B. Compressed Tablets Containing Ibandronate and Citric Acid

The enteric coating suspension prepared in Part A above is sprayed onto100 mg Ibandronate tablets, each tablet weighing 600 mg and eachcontaining:

Active Ingredients:

Ibandronate sodium 100 mg* Chelant: Citric acid 350.0 mg Excipients:Microcrystalline cellulose 132.0 mg Crospovidone 15.0 mg Magnesiumstearate 3.0 mg *This amount is calculated on an ibandronic acid basis.

Tablets having the composition set forth above are prepared as follows:

The tablets are prepared by sieving the ibandronate active ingredientand the citric acid with ½ of the microcrystalline cellulose into a twinshell blender. The blend is then mixed until uniform. Then, ½ of themagnesium stearate is added and the blend is mixed further. The blend isthen roller compacted and milled. The remaining microcrystallinecellulose and crospovidone are added and mixed until uniform. Theremaining magnesium stearate is then added and mixed until adequatelubrication is achieved. Tablets are then compressed on a rotary tabletpress.

Example XII Enteric-Coated Tablets Containing Risedronate and EDTA

Enteric-coated tablets containing risedronate and EDTA are made bypreparing a coating composition and compressed tablets containingrisedronate and EDTA, and then applying said coating composition to saidtablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Excipients:

Eudragit S100 ® (dry basis) 12.9 mg (manufactured by Röhm Pharma GmbHand Co. KG, Darmstadt, Germany) Dibutyl Phthalate 2.59 Talc 3.54 mg RedIron Oxide 1.37 mg Isopropyl alcohol 110.7 mg Acetone 24.74 mg PurifiedWater 3.1 mg

The enteric coating is prepared using the following method:

The purified water, approximately 80% of the isopropyl alcohol, and theEudragit S100 are combined while mixing to form a solution. After mixingfor at least 60 minutes, the acetone, dibutyl phthalate, and remainingisopropyl alcohol are added while mixing. Mixing continues through theremainder of the preparation. Ferric oxide and talc are added to thesolution and the resulting suspension is then mixed for at least onehour. The coating solution is mixed for at least one hour beforeproduction. The core tablets are transferred to the coating pan andpreheated with occasional jogging. Tablets are coated using a typicalpan coating process until the required quantity of coating solution hasbeen applied. Tablets are then cooled and collected in suitablecontainers.

A coating weight gain of 8.5% (total solids) is applied by spraying theabove composition onto compressed tablets containing risedronate andEDTA, prepared in Part B below.

B. Compressed Tablets Containing Risedronate and EDTA

The enteric coating suspension prepared in Part A above is sprayed onto35 mg risedronate tablets, each tablet weighing 240 mg as preparedaccording to Example IB.

Example XIII Capsules Containing Enteric-Coated Beads

Capsules containing enteric-coated beads are prepared by preparingenteric-coated beads, and then encapsulating them using a gelatincapsule. The beads consist of inert sugar spheres that are coated with apolymeric film which contains risedronate and EDTA and are preparedusing the procedure in Part A below. The beads are next enteric-coatedusing the procedure described in Part B below.

A. Risedronate- and EDTA-Coated Beads

Component mg/capsule Risedronate Sodium  30* Disodium EDTA 100 SugarSpheres, 20-25 mesh  115.6 Hydroxypropylmethylcellulose  25 PolyethyleneGlycol 3350   2.5 Purified Water 700 *This amount is calculated on arisedronate anhydrous monosodium salt basis.

The risedronate- and EDTA-coated beads are prepared as follows:

The purified water is heated and the hydroxypropylmethylcellulose isslowly added. When the hydroxypropylmethylcellulose is dispersed, thepolyethylene glycol is added and the solution is allowed to cool to 30°C. or less. The risedronate and EDTA are then passed through a mill, ifneeded, to break up any agglomerates, and then mixed with the polymersolution until uniform.

In a suitable coating column, the sugar spheres are warmed toapproximately 35° C. and then the risedronate and EDTA coatingsuspension prepared above is sprayed on by applying a coating 136%weight gain to the beads. When the spray cycle is completed, the air isturned off and the beads are cooled to room temperature.

B. Enteric-Coated Beads

Component mg/capsule Risedronate Sodium- and EDTA- 273.1 coated beads(prepared in Part A above) Eudragit L 30 D-55 ® (wet basis) 106 Talc USP16.9 Triethyl Citrate NF 3.2 Simethicone Emulsion USP 2.1 Yellow FerricOxide NF 0.04 Purified Water 225

The talc is added and the yellow ferric oxide is added to a portion ofthe purified water and mixed until uniform. The triethyl citrate and thesimethicone emulsion are added with continued mixing. The resultingpigment suspension is then passed through a screen or a suitable mill tobreak up agglomerates. The Eudragit L 30 D-55® is screened and thenadded to a suitable vessel and diluted with a portion of the purifiedwater. The pigment suspension is then added to the diluted Eudragitsuspension and mixing is continued.

In a suitable coating column the risedronate- and EDTA-coated beads arewarmed to the appropriate temperature. The enteric coating suspensionhaving the composition described in part B is sprayed on the beads. Whenthe spray cycle is completed, the air is turned off. The coated beadsare stored at 25-30° C. for a minimum of 12 hours before encapsulating.The beads are encapsulated utilizing a hard shell gelatin capsule usingan appropriate capsule filler.

Example XIV Enteric-Coated Tablets Containing Risedronate and EDTA

Enteric-coated tablets containing risedronate and EDTA are made bypreparing a coating composition and compressed tablets containingrisedronate and EDTA, and then applying said coating composition to saidtablets.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Ingredients:

Eudragit L 30 D-55 ® (wet basis) 47.8 mg (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Triethylcitrate 2.15 mg Talc 7.17mg Red Iron Oxide 0.07 mg Simethicone emulsion (30%) 0.14 mg Polysorbate80 0.14 mg Purified Water 102.6 mg 

The enteric coating is prepared using the following method:

A pigment suspension is prepared by adding polysorbate 80, ground ferricoxide, and talc to approximately two-thirds of the purified water whilemixing. The suspension is mixed for at least two hours. The 30%simethicone emulsion and the remaining water are added to the pigmentsuspension and mixed for at least 45 minutes. The Eudragit L30 D-55®solution and triethyl citrate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process. The core tablets aretransferred to the coating pan and preheated with occasional jogging.Tablets are coated, using a typical pan coating process until therequired quantity of coating solution has been applied. Tablets are thencooled and collected in suitable containers.

A coating weight gain of 10% (total solids) is applied by spraying theabove composition onto compressed tablets containing risedronate andEDTA, prepared in Part B below.

The enteric coating suspension prepared in Part A above is sprayed onto35 mg risedronate tablets, each tablet weighing 240 mg and prepared asin Example IB.

Example XV Enteric-Coated Soft Gelatin Capsules Containing Risedronateand Disodium EDTA

Enteric-coated capsules containing risedronate and EDTA are made bypreparing a coating composition and soft gelatin capsules containingrisedronate and EDTA, and then applying said coating composition to saidsoft gelatin capsules.

An enteric coating composition is prepared in the form of a lacquercontaining the following excipients, per tablet:

A. Enteric Coating Suspension Excipients:

Eudragit L 30 D-55 ® (wet basis) 200.0 mg  (manufactured by Röhm PharmaGmbH and Co. KG, Darmstadt, Germany) Dibutyl phthalate 10.0 mg Talc 30.0mg Red Iron Oxide 0.25 mg Simethicone emulsion (30%) 0.50 mg Polysorbate80 0.50 mg Purified Water  350 mg

The enteric coating is prepared using the following method:

A pigment suspension is prepared by adding polysorbate 80, ground ferricoxide, and talc to approximately two-thirds of the purified water whilemixing. The suspension is mixed for at least two hours. The 30%simethicone emulsion and the remaining water are added to the pigmentsuspension and mixed for at least 45 minutes. The Eudragit L 30 D-55solution and dibutylphthalate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process. The soft gelatincapsules are transferred to the coating pan and preheated withoccasional jogging. The soft gelatin capsules are coated, using atypical pan coating process until the required quantity of coatingsolution has been applied. Capsules are then cooled and collected insuitable containers.

A coating weight gain of 13% (total solids) is applied by spraying theabove composition onto soft gelatin capsules containing risedronate andEDTA, prepared in Part B below.

B. Soft Gelatin Capsules Containing Risedronate and EDTA

The enteric coating suspension prepared in Part A above is sprayed onto50 mg risedronate soft gelatin capsules, each weighing 764 mg and eachcontaining:

Fill Composition

Risedronate sodium 50 mg* Oleoyl Macrogol-6 Glycerides 370 mg ColloidalSilicon Dioxide 5 mg Disodium EDTA 125 mg Total 550 mg Gel ShellComposition Gelatin 123.4 mg Glycerin 44.1 mg Anhydrized Liquid Sorbitol(Sorbitol Special, 76%) 27.1 mg Purified Water 17.1 mg Titanium dioxide1.0 mg FD&C Red No. 40, E129 0.96 mg FD&C Blue No. 1, E133 0.30 mg Total214 mg Total Capsule weight 764 mg *This amount is calculated on arisedronate anhydrous monosodium salt basis.

Soft gelatin capsules having the composition set forth above areprepared as follows:

The Oleoyl Macrogol-6 Glycerides is added to a suspension tank equippedwith an overhead mixer. The risedronate sodium, disodium EDTA, colloidalsilicon dioxide are passed through a mill and added to the OleoylMacrogol-6 Glycerides with continued mixing. The mixture is blended forapproximately 60 minutes. The blend is then deaerated and ready forfilling into capsules. With mixing, the glycerin, sorbitol special, andpurified water are combined in a heated vacuum vessel. Heat is applieduntil the temperature reaches at least 80° C., then the gelatin is addedand mixed for 75 minutes. The gel mass is examined for completedissolution of particles. If needed continued heating and mixing isapplied until there is no visual evidence of undissolved particles. Thegel mass is deaerated, then the titanium dioxide, FD&C Red No. 40 andFD&C Blue No. 1 are added with continued mixing. The gel mass isdischarged into heated gel holding tanks for subsequent processing. Thefill material is then encapsulated on a soft gelatin capsule filler.

Example XVI Enteric-Coated Tablet for Releasing Citric Acid in theJejunum and Risedronate in the Ascending Colon

An enteric-coated layered tablet containing risedronate sodium in onelayer and citric acid in a separate layer is designed so that the citricacid is released in the jejunum and the risedronate is released in theascending colon. The tablet is prepared according to the followingmethod:

Active layer:

Component mg/tablet Risedronate sodium  50 mg*Hydroxypropylmethylcellulose 100 mg  Starch 1500 90 mg MicrocrystallineCellulose 50 mg Stearic Acid 10 mg Purified water 60 mg *This amount iscalculated on a risedronate anhydrous monosodium salt basis.

A mixture of risedronate sodium, hydroxypropylmethylcellulose, starch1500, and microcrystalline cellulose is wet granulated in a high shearmixer with purified water. The granulation is then sieved and dried at30° C. for 12 hours. Then the stearic acid is added and mixed in a lowshear mixer until uniform, and the granulation is discharged into afiber drum.

Citric Acid layer:

Component mg/tablet Citric acid 150 mg  Lactose, Hydrous 100 mg Polyvinylpyrrolidone 10 mg Microcrystalline Cellulose 50 mg Stearic Acid10 mg Purified water 65 mg

A mixture of citric acid, lactose, polyvinylpyrrolidone andmicrocrystalline cellulose is wet granulated in a high shear mixer withpurified water. The granulation is then sieved and dried at 30° C. for12 hours. Then the stearic acid is added and mixed in a low shear mixeruntil uniform then the granulation is discharged into a fiber drum.Tablets are compressed at a weight of 620 mg on a layer tablet press.

The enteric coating has the following composition per tablet:

Component mg/tablet Eudragit L100 ® 62 Triethylcitrate 12.5 Isopropylalcohol 600 Purified water 100

The triethyl citrate is added to the purified water and isopropylalcohol with continued mixing. The Eudragit L 100® is added withcontinued mixing. In a suitable coating pan, the compressed layeredtablets (10 kg) containing risedronate in one layer and citric acid in aseparate layer are warmed to about 30-35° C. The enteric coatingsuspension is sprayed onto the tablets at approximately 50 grams/minute.When the spray cycle is completed, the temperature is reduced and thetablets are removed and dried at 30-35° C. for approximately 1 hour.

Example XVII

A 65 kg woman diagnosed with postmenopausal osteoporosis is prescribedthe enteric-coated oral dosage form of Example 1, to be taken onceweekly, comprising 35 mg risedronate and 100 mg Disodium EDTA. Thepatient takes the oral dosage form with breakfast once per week. Abiopsy of iliac crest bone is taken at two years and reveals an increasein mean wall thickness of the remodeling units compared to her baselinebiopsy.

Example XVIII

A 70 kg man diagnosed with prostate cancer and high bone turnover isprescribed the enteric-coated oral dosage form of Example 1, to be takenonce weekly, comprising 35 mg risedronate and 150 mg citric acid. Thepatient takes the oral dosage form once per week, immediately beforegoing to sleep. The patient does not experience upper GI irritation ordiscomfort.

Example XIX

A randomized, open-label, single-dose, single-center, 8-treatment,parallel-group study is performed to compare absorption of oral, fastedimmediate release risedronate sodium tablets with fed and fastedrisedronate sodium plus EDTA delivered to different locations in thelower GI tract. The study consists of one 72-hour period.

The following treatments are administered to treatment groups A-H:

Treat- ment Number of Group Subjects Dose Delivery/Status A 10 35 mgrisedronate sodium tablet Stomach/fasted B 10 35 mg risedronate sodium +100 jejunum/fasted mg disodium EDTA C 10 35 mg risedronate sodium + 100jejunum/fed mg disodium EDTA D 10 35 mg risedronate sodium + 100terminal ileum/ mg disodium EDTA fasted E 10 35 mg risedronate sodium +100 terminal ileum/ mg disodium EDTA fed F 10 35 mg risedronate sodium +100 ascending colon/ mg disodium EDTA fasted G 10 35 mg risedronatesodium + 100 ascending colon/ mg disodium EDTA fed H 10 35 mgrisedronate sodium + 100 descending colon/ mg disodium EDTA fasted

For fasted administration, subjects fast overnight and the dose isadministered in the morning. Subjects continue to fast until the drug isreleased at the specified site.

For fed administration (Treatment Groups C, E, and G), subjects are feda light breakfast and at approximately 3 hours later subjects take thestudy medication. Immediately following the passing of the studymedication from the stomach, these subjects eat a breakfast. Subjectscontinue to fast until 2 hours after the drug is released at thespecified site.

Ratio of Fed to Fasted Urine Recovery for Different Sites of Release

Urinary Recovery (% of dose) Location of Release Ratio Fed/FastedJejunum 0.959 Ileum 1.131 Ascending Colon 1.560

A ratio near 1 indicates that the absorption is the same with or withoutfood.

Example XX Enteric-Coated Tablets Containing Risedronate and EDTA

Enteric-coated tablets containing risedronate are prepared using asimilar method as described in Example I. A coating preparation isprepared as described below.

A. Enteric Coating Suspension

Ingredients:

Eudragit FS30D (wet basis) 57.6 mg Eudragit FS30D (dry basis) 17.3 mgTriethylcitrate 0.86 mg Talc 5.18 mg Red iron oxide 0.07 mg Simethiconeemulsion (30%) 0.21 mg Polysorbate 80 0.55 mg Purified water 160.1 mg 

A pigment suspension is prepared by adding polysorbate 80, ground ferricoxide, and talc to approximately two-thirds of the purified water whilemixing. The suspension is mixed for at least two hours. The 30%simethicone emulsion and the remaining water are added to the pigmentsuspension and mixed for at least 45 minutes. The Eudragit FS30Dsolution and triethylcitrate are combined and mixed for at least 45minutes. The pigment suspension is then added to the Eudragit solutionand mixed for 30 to 60 minutes. The resulting coating suspension isscreened and mixed throughout the coating process.

The compressed risedronate tablets as described in Example I aretransferred to the coating pan and preheated with occasional jogging.The compressed tablets are coated with the Enteric-Coating Suspensionusing a typical pan process until the required coating has been applied.

All documents cited are, in relevant part, incorporated herein byreference; the citation of any document is not to be construed as anadmission that it is prior art with respect to the present invention.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. An oral dosage form comprising: (a) about 150 mg of a bisphosphonateselected from the group consisting of a risedronate and salts thereof;(b) from about 55 mg to about 500 mg of an ethylenediaminetetraaceticacid (EDTA) or a pharmaceutically acceptable salt thereof; and (c) adelayed release mechanism to deliver the risedronate and the EDTA in thelower gastrointestinal tract, wherein the oral dosage form isadministered according to a continuous schedule having a once monthlydosing interval.